Hi, We had a persistent diaper rash, luckily only a few popped pistules - but they were nasty. I have a few suggestions that I found on the internet and got from our pediatricians nurse that were helpful for me:
Rash: for the open pistules, definitely diaper free time. After wiping from dirty diaper or bath - let rash air dry and then apply a VERY SMALL amount of neosporin/bacitracin to open sore. Then cover the antibiotic with a layer of diaper cream (I used weleda) to seal it from urine/feces. B/c we use cloth (FuzziBunz) I switched to diposables while using the diaper cream.
I also read that when the rash is starting or not too bad (b/c it will likely come back) too spray area with diluted apple cider vinegar. This will sting a regular rash, but won't sting a yeast rash. I kept a small spray bottle with 50% mix of apple cider vinegar and water on changing table and would spray after wiping poop. I occassionally put a thin layer of yogurt on rash for a change of treatment.
Bath: you can also put a couple capfuls of apple cider vinegar in the bath water. Also some yogurt in bath water can be helpful as well.
Diapers: you need to treat your cloth diapers like this even for a couple weeks or so after rash clears up. This is how I treated my FuzziBunz:
Grapefruit Seed Extract - http://www.vitacost.com/NutriBiotic-GSE-Liquid-Concentrate-Grapefruit-Seed-Extract
Oxygen Bleach http://www.walmart.com/ip/Oxygen-Cleaner-All-Purpose-Stain-Remover-Powder/13908578
1. cold water pre-rinse - sometimes use baking soda here to neutralize urine smell
2. hot wash with half scoop charlie's soap, 1-2 scoops oxygen cleaner, 80 drops (yup, eighty) Grapefruit Seed Extract
3. cold rinse that is part of wash cycle
4. extra cold rinse cycle
5. line dry in sun if weather permits.